The collapse occurred around 11 a.m. in downtown Houston between Texas Ave. and Preston St, according to KPRC 2 News. At least four of the workers were trapped beneath the crumbling scaffolding. The workers were working on an apartment complex.

All six workers were rushed to hospitals Friday morning with serious, but not lethal wounds, according to a statement released by the Houston Fire Department. Other details on their conditions are still incoming.

Responders are continuing to search the debris for others that may be trapped inside, including pedestrians.

Construction officials on the scene have reported a headcount has revealed all workers are accounted for. Still, there are concerns of further collapses as the scaffolding is compromised.

“Anytime you have a collapse, a secondary collapse is not only probable, it’s highly likely,” Ruy Lozano of the Houston Fire Department told KPRC 2 News.

The apartment complex where the accident occurred is owned by Finger Companies. They released a statement Friday, saying, “We are monitoring the situation very closely and working alongside authorities as we try to determine the cause of this accident. In the meantime we are grateful to the first responders on the scene and praying that everyone is OK.”

Injuries and deaths in construction are shockingly common. This incident follows a construction crane collapsing in Atlanta on Thursday. In a typical year, 20 percent of all on the job deaths occurred on construction sites, according to statistics from the Occupational Safety & Health Administration. The largest contributor to the construction worker deaths is falls, representing nearly 40 percent of fatalities.

OSHA lists the “big four” of construction injuries and deaths as falls, electrocutions, struck by object, and caught-in/between. Together the big four account for more than half of construction-site injuries. OSHA is working to reduce their impact. The administration estimates that eliminating those big four causes would save more than 500 workers' lives a year.